Vacuum receiver and separator



Feb. 6, 1962 M. D. WOODRUFF VACUUM RECEIVER AND SEFARATOR 2 Sheets-Sheet1 Filed July 1, 1959 mm m mw w W Feb. 6, 1962 M. D. WOODRUFF 3,019,901

VACUUM RECEIVER AND SEPARATOR Filed July 1, 1959 2 Sheets-Sheet 2INVENTOR. fifiJf/(f 0. WOODZl/ff BY 10 p'n'v mu irrotwzr United StatesPatent 3,919,991 "ACUUM RECEIVER AND SEPARATOR Maurice D. Woodruii,Springfield, Ohio, assignor to The ggriier Bros. (30., Springfield,Ghio, a corporation of Filed July 1, 1959, Ser. No. 824,277 18 Claims.(Cl. 209-211) This invention relates to methods of and apparatus fortreating a liquid stock containing rejecta-ble and acceptable solids insuspension, and, although not so limited, has especial reference toinstallations in which cleaning of pulp stock and the like is effectedin stages.

The object of the invention is to simplify the construction as well asthe means and mode of operation of stock cleaning equipment, wherebysuch equipment may not only be economically manufactured, but will bemore eflicient and satisfactory in use, adaptable to a wide variety ofapplications, and be unlikely to get out of order.

A further object of the invention is to introduce in a systeminstallation as described a cleaner-separator having special utility inthe removal of sand, metal and other foreign material, especially thathaving an abrasive action upon the interior walls of the cleaningdevices.

Another object of the invention is to introduce a cleaner-separator asdescribed subsequent in a system installation to primary cleaning of theliquid stock and at a location to take advantage of a reduction inconsistency of the stock favorable to removal of the heavy and abrasivematerial.

A further object of the invention is to present in a system as describeda generally new article of manufacture in the form of a vacuum receiverand separator device combining the functions of the vacuum receiver andhydrocyclone separator as heretofore known in the art and introducing anew mode of carrying off the rejected solids fraction.

Still another object of the invention is topresent a vacuum receiverhydrocyclone separator combination in which both the accepted andrejected solid fractions are carried off through the apex end of thehydrocyclone.

A further object of the invention is to provide a stock equipmentpossessing the advantageous structural features, the inherentmeritorious characteristics and the mode of operation herein mentioned.

With the above and other incidental objects in view as will more fullyappear in the specification, the invention intended to be protected byLetters Patentconsists of the features of construction, the parts andcombinations thereof, and the mode of operation as hereinafter describedor illustrated in the accompanying drawings, or their equivalents.

Referring to the accompanying drawing wherein is shown one but obviouslynot necessarily the only form of embodiment of the invention,

FIG. 1 is a view inelevation, partly diagrammatic, of a vacuum receiverand separator device in accordance with the illustrated embodiment ofthe invention, showing it installed in a cleaning system and receivingliquid stock for treatment from a primary cleaning stage;

FIG. 2 is a top view of the vacuum receiver and separator device of FIG.1; and

FIG. 3 is a diagram of a system installation showing an application ofthe invention to the pulp treating industry.

Like parts are indicated by similar characters of reference throughoutthe several views.

Referring to the drawings, a vacuum receiver and separator device inaccordance with the illustrated embodiment of the invention comprises,as shown in FIG. 1, a shell having a cylindrical base end portion 11 anda conical portion 12 terminating in an apex end 13. The latter is openand has fastened thereto an adapter 14 by which the apex end of thedevice is communicated with the interior of a collecting tank 15. Thelatter has valves 16 and 17 at its opposite ends by which it mayperiodically be flushed free of collected reject material as willhereinafter more clearly appear. The base end of the device is closed byan insert 18. The interior of the shell 10 is open throughout its lengthand contains a liquid pond, the upper level of which lies within thebase end of the device, as for example, at a point indicated by line 19.An inlet 21 is mounted to the base end of the device to dischargetangentially into the interior thereof at a point below the liquid level19. The introduced stock or liquid suspension accordingly causes avortex movement in the shell 10 and a consequent separation of entrainedsolids which move to the periphery of the conical portion 12 and areurged downwardly to issue from the device by way of the apex outlet 13.The acceptable fraction, on the other hand, moves toward thelongitudinal axis of the device and travels in an opposite directiontoward the base end of the device. There it has access to the open endof an overflow nozzle 22 which, in the illustrated embodiment of theinvention, has an open inner end facing the base end of the device andtermi.

hating beneath the liquid level 19 while extending in the opposite senseinto and through the conical portion 12 of the device. In the oneinstance the nozzle 22 is shown as inclining toward the wall of portion12 to define a duct 23 projecting laterally outside the device. In theother illustrated instance the nozzle 22 is shown as forming one end ofa pipe or conduit 24 extending longitudinally through the conicalportion 12, through the open apex end 13 and through the adapter 14 andtank 15. accepted fraction is constrained to move to the exteriorsurface of the conduit and follows along such surface upwardly or towardthe open end of nozzle 22 where it may enter and then reverse itsmotion, traveling inwardly of the conduit 24 to and through the apex end13 and outside the device.

Through a duct 25, the interior of the base end 11 of the shell 10 ismade into a vacuum chamber, a vacuum applying means being connected tothe vacuum receiver and separator device through the duct 25.

of the liquid suspension. In connection with the -admis-' sion of thestock for treatment to the shell 10' it will be understood that thearrangement of inlet 21 is such as to produce a vortex motion within theshell 10 having the effect of depressing the center of liquid level 19,as liquid flow into the centrally positioned nozzle takes place. in theinner one of the double spirals taking place in the shell is drawn bythis vortex movement into the nozzle as it reaches the open mouththereof.

In the illustrated example the vacuum receiver and separator device isdisclosed as installed in a system for the treatment of pulp stock,preliminary to paper making, wherein the device functions asMagna-Cleaner, removing metallic and like abrasive particles from theflowing stock. In accordance with a feature of the invention the deviceis located between primary and secondary cleaning stages whereinfavorable conditions prevail for the removal of such particles. TheMagnet-Cleaner is distinguished from hydrocyclonic cleaners as may beused in the primary and other cleaning stages by being relativelyoversize in construction, characterized by operation under conditions ofhigh capacity and low pressure drop, these being conditions conducive toa movement of heavy particles through the apex end 13 of the separatorwhile the body In the event of theme of the conduit 24 the The acceptedfraction rising along the pipe 24- proper of the stock and accompanyingliquid forms the acceptable fraction and moves to the nozzle 22. It isfurther distinguished by an absence of continuous discharge of the heavyfraction.

Referring to FIG. 3, showing a wood pulp treatment system in diagram,the vacuum receiver and separator is shown located between a primarycleaning stage 26 and a secondary cleaning stage 27, receiving therejects from primary stage 26 through a manifold 28 and delivering theacceptable fraction as separated therein to the secondary stage 27. Inthe system as illustrated a reservoir 29 of white water supplies thesystem with liquid through an outlet line 31. Fibrous stock material isfed to the system by a line 32 and the stock and liquid are combined toform a liquid stock or liquid suspension in a line 33 in which is a pump34. The latter places the liquid suspension under pressure and deliversit to the first cleaning stage comprising a battery of conicalhydrocyclones 35. The line 33 constitutes a common inlet for the severalhydrocyclones 35 which, in accordance with their usual function, producea double spiral movement in their interiors, light acceptable fibersmaking up one movement and iiowing out the base end of the hydrocyclonewhile liquid, dirt, foreign material and non-accepted fibers form theother spiral and issue through the apex end. The accepted materialleaves the hydrocyclone by way of an outlet nozzle 36 and enters a line37 common to all of the several hydrocyclones 35. The line 37 leads to ahead box 38 which in turn supplies paper making machinery 39. Analternative line 41 leads back to liquid suspension line 33 so that thesurplus pulp not required by the paper machine may be returned to thesystem. The alternative use of the line 41 is under the control of avalve 42 in the line 41 and a valve 43 in the line 37.

The rejected fraction issuing from the apex ends of the hydrocyclones isdischarged through respective conduits 44 to the aforementioned manifold28. The latter is of a wide diameter to accommodate the full dischargeof the battery of hydrocyclones in a portion only of its full diameter,leaving an upper portion of the diameter to form a, vacuum chamber, themanifold, being connected at its upper end through a conduit 45 with theduct 25 and line leading to the vacuum producing means. The resultingarrangement is that the manifold 28 is under vacuum or negativepressure. No opportunity thus is afforded for air to be drawn into thehydrocyclones through the apex end thereof to join with the acceptedfraction. The high rotation speed of the vortices results in a liquidfree space on the aXis of the hydrocyclone and any air bubbles in theliquid are forced into this liquid free space or air core. The air coreextends the full length of the hydrocyclone and communicates with themanifold 28. With a vacuum existing in the manifold 28, the air is drawninto it and passes through conduit 45 to the vacuum producing means. Themanifold 28; is inclined for a free flow to the vacuum receiver andseparator shell and is selectively located to have that part of thelength thereof receiving the conduits 44 above the liquid level 19 orwith at least a port-ion of the diameter thereof above such liquidlevel. Beyond its connection with the several hydrocyclones 35 themanifold, 28 dips and through adapter elbows 46 and 47 communicates withinlet 21 to the shell 10. Dropping any. selected distance from themanifold 28, the liquid, suspension achieves an elevated velocity.Accordingly its tangential. discharge into. the shell 10 by way of inlet21 causes, the liquid in the pond contained in shell- 10 to rotatesetting up the vortex pattern as described. The centrifugal forcesestablished are suflicient to throw abrasive materials to the peripherywhere they descend to the apex end 13 and are discharged into thecollecting chamber 15. Periodically, as before noted, the valves 16 and1.7 are opened and the collecting chamber flushed out. Means to supplydilution water to he manifold 28 is provided in the form of a valvecontrolled line 40 extending from water supply line 31 to the left-handend of the manifold or header member receiving the rejects from theprimary cleaners.

The extension 24 of overflow nozzle 22 extends through and beyond thechamber 15. As noted, the accepts from the vacuum receiver andseparator, whether issuing from axial conduit 24 or from alternativeconduit 23, are discharged into a line 48 leading to the secondarycleaning stage 27. The line 43 is supplied with make-up water from watersupply line 31 by way of a branch 49 thereof under control of a valve51. A pump 52 provides for admission of the liquid suspension to thesecondary stage under pressure. The stage 27 comprises a battery ofhydrocyclones 53 which operate like the hydrocyclones 35 to produce anacceptable fraction issuing through the base ends of the hydrocyclonesand entering a line 54. Through this line, under control of a valve 55,they are admitted to the aforementioned return line 41 downstream of thevalve 42 and thence conducted back to the liquid suspension supply line33 for reintroduction into the primary stage 26. The rejects from thesecondary stage 27 discharge, to a line 56 and are thereby conducted toa tertiary stage 57 comprising one or more hydrocyclones 58. Make-upwater is supplied to line 56 by way of a branch 59 from supply line 31.A pump 61 supplies the liquid suspension to stage 57 under pressure. Theaccepts from the tertiary stage are fed into the line 54 as indicatedwhile the rejects are discharged into a tank 62 from which they may bewithdrawn by a pump 63 and delivered through a line 64 to a refiner andeventual return to the stock supply line 32. The salvaging of the finalrejects is a feature of the invention made possible by the use of thevacuum receiver and separator in its function of removing abrasivematerials. The vacuum receiver and separator is also useful as noted inobviating wear, it being understood that the whirling motions induced inthe, hydrocyclones have an abrasive action on the walls thereof. As. anexample of the advantageous use of the invention, in the production ofground wood pulp the abrasive grains from the grinding wheel become dulland break off and are found in the pulp. The pulp is pumped at such aconsistency that these grains appear with the rejects from the primarycleaning stage and through the secondary pump where they cause some Wearand then go through the secondary cleaners where their more concentratedform produces additional and more severe wear. If this is followed witha third stage, the tertiary pump and cleaner have a still furtherconcentrated amount of abrasive rejects and wear becomes still more.severe. In addition to the abrasive grains, a system operation producespipe scale, metal particles, and other abrasive materials accidentallyentering the system. The instant receiverseparator is capable ofremoving all of this heavy fraction. Concentrated wear as has heretoforetaken place in secondary and tertiary pump and cleaner elements isavoided.

A valve controlled line 65- provides additional water from line 31 tosupply pump 63.

The liquid level 19 of the liquid pond in shell 10 is maintainedsubstantially constant through a control system 66 sensing vacuumpressure in the upper end of shell 10 through a connection 67 andsensing liquid pressure in the shell through a connection 68. The systemcontrols the setting of a valve 51 through a means 69 and it will beunderstood acts to admit more or less water to the line 43 as the liquidlevel 19 falls and rises. The control system is schematically disclosed,being the result of a combination of known instruments and devicesproducing a heretofore known result. The receiver-separator is fittedwith differential pressure means including a cell located above theliquid level to measure the vacuum pressure and another cell locatedbelow the liquid level to measure the liquid pressure. By adjustment,any desired liquid level canbe maintained inside the receiver, by thecontrol means positioning the automatic valve supplying the makeupwater.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions detailconstruction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but one of several modes of putting the invention into effect,and the invention is therefore claimed in any of its forms ormodifications within the legitimate and valid scope of the appendedclaims.

Having thus described my invention, I claim:

1. A method of cleaning a liquid stock containing acceptable andrejectable solids in suspension, including the steps of flowing theliquid stock through primary and secondary cleaning stages in which thestock is subjected to hydro-cyclonic separating action under conditionsof determined pressure drop and flow rate, intermediate said stagesremoving heavy and abrasive particles by subjecting the liquid stock tohydro-cyclonic separating action under conditions of low pressure dropand high flow rate, as compared to corresponding conditions in theprimary and secondary cleaning stages, and carrying out saidhydro-cyclonic separating action in the presence of applied vacuum byconnection to a vacuum source.

2. A method of cleaning a liquid stock containing acceptable andrejectable solids in suspension, including the steps of flowing theliquid stock through a primary cleaning stage, diluting the materialrejected by said primary stage and flowing it through a secondarycleaning stage, and between said stages and in the presence of appliedvacuum putting the material rejected by said primary stage through anintermediate stage under conditions of low pressure drop and high flowrate as compared to corresponding conditions in said primary cleaningstage, said conditions being favorable to separating out of heavy andabrasive particles.

3. A method of cleaning a liquid stock containing acceptable andrejectable solids in suspension, including the steps of flowing theliquid stock through successive cleaning stages reducing the consistencythereof, and at a point between selected stages and in the presence ofapplied vacuum putting the material rejected in the immediatelypreceding stage through an intermediate stage under conditions of lowpressure drop and high flow rate as compared to corresponding conditionsin the said immediately preceding state, said conditions being favorableto a separating out of heavy and abrasive particles.

4. Apparatus for cleaning a liquid stock containing acceptable andrejectable solids in suspension, including primary and secondaryhydro-cyclonic cleaners, means for flowing the liquid stock of saidprimary cleaner and flowing the rejects from said primary cleaner towardsaid secondary cleaner, another hydro-cyclonic cleaner intermediate saidprimary and secondary cleaners and in the path of flow to said secondarycleaner, said other hydro-cyclonic cleaner receiving the rejects fromsaid primary cleaner and delivering an accepted fraction thereof to saidsecondary cleaner, said other hydro-cyclonic cleaner having a large flowcapacity under conditions of low pressure drop relative to said primaryand secondary cleaners whereby to provide conditions favorable to aremoval of heavy and abrasive particles, and means for applying a vacuumin said hydro-cyclonic cleaner.

5. Apparatus for removing rejectable solids from a liquid stockcontaining acceptable and rejectable solids in suspension, includinghydro-cyclonic cleaning means, a

vacuum receiver and separator holding a pond of liquid and formed forhydro-cyclonic separation, inlet means for introducing tangentially intosaid vacuum receiver and separator below the level of said pond therejects from said cleaner, said introduction being with a forcesufficient to produce a vortex in said pond to which heavy and abrasivesolids settle toward One end of said vacuum receiver and separator whileanother fraction moves toward the opposite end thereof, means to conductsaid other fraction out of said vacuum receiver and separator, means forcreating a vacuum chamber above the level of said pond, and a conduitcomprised in said inlet means extending from said cleaning means to saidvacuum receiver and separator and communicating with said vacuumchamber.

6. Apparatus according to claim 5, characterized in that said conduit isarranged over a part of its length with at least a part of its internaldiameter higher than the level of said pond.

7. Apparatus for removing rejectable solids from a liquid stockcontaining acceptable and rejectable solids in suspension, includingcleaning means, means introducing a liquid stock into said cleaningmeans, the rejected solids issuing from one end of said cleaning means,a conduit conducting the rejected solids away from said cleaning means,vacuum applying means communicating with said conduit, a hydrocyclonehaving an apex outlet and an elongated base portion communicating withsaid vacuum applying means, a pond of liquid in said hydro-cyclonehaving its level in said base portion, an inlet to said hydrocyclonereceiving the rejects from said cleaning means through said conduit anddischarging tangentially below the level of said pond, a rejectablefraction of the solids issuing through said apex and an acceptablefraction moving toward the base of the hydro-cyclone, and means forcarrying ofi said acceptable fraction.

8. Apparatus according to claim 7, characterized by means formaintaining the level of said pond substantially constant.

9. Apparatus according to claim 7, characterized in that said conduit isarranged over a part of its length with at least a part of its internaldiameter higher than the level of said pond.

10. Apparatus for removing rejectable solids from a liquid stockcontaining acceptable and rejectable solids in suspension, including avacuum receiver and separator device having a base end and an apex end,the apex end being an outlet for rejectable solids, means formaintaining a pond of liquid in said device the level of which is in thebase end, means for creating a vacuum in the base end of said deviceabove the liquid level, means for supplying a liquid stock into thedevice below the liquid level tangentially with sufiicient force tocreate a vortex in the pond, a rejectable fraction moving toward theapex end and an acceptable fraction moving toward the base end, andmeans for carrying off the acceptable fraction.

11. Apparatus according to claim 10, characterized in that said lastnamed means comprises an outlet facing the said base end of the device.

12. Apparatus according to claim 10, characterized in that said lastnamed means comprises an outlet conduit extending through the apex endof the device and longitudinally through the interior thereof to thebase end of the device and having an open inner end terminating in thesaid base end of the device below the level of the pond.

13. Apparatus for removing rejectable solids from a liquid stockcontaining acceptable and rejectable solids in suspension, including avacuum receiver and separator device having a closed base end and anopen apex end, a conduit entering said device through the open apex endand extending longitudinally of the device toward the base end andhaving an open inner end, a tangential inlet for the admission of liquidstock, the whirling motion of the liquid producing a rejectable fractionmoving to said apex and issuing therefrom around said conduit, andfurther producing an acceptable fraction moving along the exterior ofsaid conduit toward the base end of the device and entering the openinner end of said conduit to flow in a reverse direction through saidconduit out of the device, means maintaining a liquid pond in saiddevice submerging said inlet and the open inner end of said conduit, andmeans for creating a vacuum in said device in the base end thereof abovethe liquid level.

14. Apparatus for removing rejectable solids from a liquid stockcontaining acceptable and rejectable solids in suspension, including avacuum receiver and separator device having a closed base end, an openapex end, a conduit having one end opening to the interior of saiddevice in the base end thereof and extending outside said device at itsother end, an inlet for the admission of liquid stock arranged fortangential discharge to produce a whirling motion of the suspensionresulting in the forma tion of a rejectable fraction moving to said apexend and issuing therefrom and further producing an acceptable fractionmoving toward the base end of the device and entering the open inner endof said conduit, means maintaining a liquid pond in said devicesubmerging the open inner end of said conduit and said inlet, and meansfor creating a vacuum in said device in the base end thel'eol above theliquid level.

15. Apparatus according to claim 14, characterized in that said conduithas its open inner end facing the base end of the device and extends ininclined relation to the longitudinal axis of the device to and throughthe side thereof.

16. Apparatus according to claim 14, characterized in that said conduitis longitudinally disposed in said device passing through the apex endthereof for discharge of both the rejectabl'e and acceptable fractionsthrough the apex end of the device.

17. Apparatus for removing rejectable solids from a liquid stockcontaining acceptable and rejectable solids in suspension including avacuum receiver and separator device having a closed base end and anopen apex end, means for maintaining a pond of liquid in said device aninlet for the tangential discharge of liquid stock into said device toinduce a separation of the rejectable and acceptable fractions, saidinlet being below the level of said pond whereby to create a vortex insaid pond, and a conduit in said device to carry all the acceptablefraction, said conduit havin its open end in the base end of said devicebelow the level or" said pond and intermediate said inlet and the apexend of the device, and means for creating a vacuum in the base end ofsaid device above the liquid level.

18. A method of cleaning a liquid stock containing acceptable andrejectable solids in suspension, including the steps of flowing theliquid stock through successive cleaning stages, at a point betweenselected stages putting the material rejected in the immediatelyprecedinng stage through an intermediate stage under conditions of lowpressure drop and high flow rate as compared to corresponding conditionsin the said immediately preceding stage, said conditions being favorableto a separating out of heavy and abrasive particles, and carrying outthe operation of said intermediate stage in the presence of appliedvacuum by connection to a vacuum source.

References Cited in the file of this patent UNITED STATES PATENTS1,301,544 Crombie Apr. 22, 1919 2,817,441 Leernan Dec. 24, 1957'2,870,908 Fitch Jan. 27, 1959 2,886,287 Croley May 12, 1959 2,931,503Clark Apr. 5, I960 FOREIGN PATENTS 1,098,193 France Mar. 2, 1955

